The human ear is divided into the outer, middle and inner ear. The outer ear includes the pinna (earlobe) and the auditory (ear) canal. The earlobe collects sound waves into the ear canal. Unlike in many other animals, the human earlobes do not move. This has not always been the case, as vestigial muscles whose function is to move the ear still exist in the human body.



The structure of the ear.

Your earlobe funnels sound waves into your outer ear canal. The waves travel along this passage until they hit your tympanic membrane (=eardrum), and cause it to vibrate. As a result, your ossicles (the smallest bones in the human body) start moving. They, in turn, pass on vibrations to a thin layer of tissue at the entrance of your inner ear called the oval window. The movement of the oval window then sets off wave-like motions in the fluid in your cochlea.

The hearing part of the inner ear and is called the cochlea which comes from the Greek word for ‘snail’ because of its distinctive coiled shape. The cochlea, which contains many thousands of sensory cells (called ‘hair cells’), is connected to the central hearing system by the hearing or auditory nerve. The cochlea is filled with special fluids which are important to the process of hearing.

The semi-circular canals and the round window are also located in the inner ear. They help us sense movement and the position of the head.